Interfacial and Solution Aggregation Behavior of a Series of Bioinspired Rhamnolipid Congeners Rha-C14-C x ( x = 6, 8, 10, 12, 14)
Interfacial and Solution Aggregation Behavior of a Series of Bioinspired Rhamnolipid Congeners Rha-C14-C x ( x = 6, 8, 10, 12, 14)
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一系列仿生鼠李糖脂同系物 Rha-C14-C x ( x = 6, 8, 10, 12, 14) 的界面和溶液聚集行为
DOI：
10.1021/acs.jpcb.1c09435
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Pemberton, Jeanne E.
中科院分区：
文献类型：
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作者：
Palos Pacheco, Ricardo;Kegel, Laurel L.;Pemberton, Jeanne E.
鼠李糖脂是由微生物产生的糖脂，具有出色的表面活性剂特性。它们是一类生物表面活性剂，是当前特种合成表面活性剂的可生物降解且无毒的替代品的潜在候选者。基于我们之前开发高效实用的化学方法来合成鼠李糖脂的努力，我们现在可以探索鼠李糖脂性质的可调性。在这里，我们探讨了一系列通用结构 Rha-C14-Cx 的单鼠李糖脂的非对映体混合物的两个脂质尾对称性对溶液自组装和空气/水界面吸附的影响。这些分子的阴离子形式在 pH 8 时的表面活性通过表面张力测定法描述。使用动态光散射和时间分辨荧光猝灭光谱测定它们在水溶液中的聚集行为特征，包括流体动力学半径、聚集数和聚集形态。发现该系列的解决方案聚合行为意外地以非单调方式变化。这是通过每个系列成员的分子结构属性来解释的，这些属性导致这些表面活性剂各个部分各自的分子间相互作用存在差异。
Rhamnolipids are glycolipids produced by microorganisms with outstanding surfactant properties. They are a class of biosurfactants that are potential candidates for biodegradable and nontoxic replacements of current specialty synthetic surfactants. Building on our previous efforts in developing an efficient and practical chemical methodology to synthesize rhamnolipids allows us to now explore the tunability of rhamnolipid properties. Here, we explore the impact on solution self-assembly and adsorption at the air/water interface of symmetry of the two lipid tails for diastereomeric mixtures of a series of monorhamnolipids of the generic structure Rha-C14-Cx. Surface activity of the anionic forms of these molecules at pH 8 is described by surface tensiometry. Characteristics of their aggregation behavior in aqueous solutions including hydrodynamic radius, aggregation number, and aggregate morphology are determined using dynamic light scattering and time-resolved fluorescence quenching spectroscopy. The solution aggregation behavior of this series is found to unexpectedly vary in a nonmonotonic fashion. This is explained by molecular structural attributes of each series member that result in differences in the respective intermolecular interactions of various parts of these surfactants.